Mutation
The picture to the left shows one of the mutations within the KCNQ1 gene that causes Long-QT Syndrome. When the gene was sequenced it revealed a heterozygous single base exchange shown within the black box of the G becoming an A. This exchange resulted in a misense mutation also shown in the black box at the bottom of the R becoming a Q. This mutation had previously been known to be associated with Long-QT Syndrome type 1. [1]
References
[1] Alessandra Moretti et al. Patient-Specific Induced Pluripotent Stem-Cell Models for Long-QT Syndrome. The New England Journal of Medicine. Vol. 363 No. 15. Oct. 2010. p. 1397-1409.